The present invention relates to a polymer processing machine, and particulary relates to an apparatus for feeding colorant to the machine.
Some types of polymer processing machines, such as molding or extrusion machines, use colorant in the form of small pellets which are fed to the machine through a hopper. The colorant is poured into the hopper from a container. The pellets can be accidently spilled from the container or the hopper onto the floor or adjacent machinery.
For example, as shown schematically in FIG. 1, a known colorant feeding system 10 includes a hopper 12 with an open upper end 14 for receiving colorant. An outlet in the form of a tubular neck 16 at the bottom of the hopper 12 delivers the colorant to a feeder block 18. An auger 20 with a stepper motor 22 drives the colorant along an axis 23 from left to right, as viewed in FIG. 1, from the feeder block 18 through an adapter 24 which couples the feeder block 18 to the polymer processing machine (not shown). An operator controls this colorant feeding process by the use of a controller 26 with an instrument panel 28. As noted above, the colorant can be spilled onto the floor or adjacent machinery when it is being poured into the open upper end 14 of the hopper 12.
In an alternative arrangement, as shown schematically in FIG. 2, the hopper 12 is omitted and a coupler 30 is used to couple a container 32 of colorant to the feeder block 18. The coupler 30 comprises a tubular structure through which the colorant can flow from the container 32 to the feeder block 18 under the force of gravity. A neck 34 at the lower end of the coupler 30 is configured as an outlet which is substantially the same as the outlet 16 at the bottom of the hopper 12. A rotatable cap 36 at the upper end of the coupler 30 receives the neck 38 of the container 32. The coupler 30 is thus configured to receive and support the container 32 above the feeder block 18 in an overturned position such that the colorant can flow from the container 32 into the feeder block 18 through the coupler 30.
A slide gate 40 on the coupler 30 operates in a known manner to open and close the flow path through the coupler 30, and thereby to control the flow of colorant from the container 32 into the feeder block 18. However, the colorant can be spilled from the container 32 when it is being mounted on, or removed from, the cap 36 at the upper end of the coupler 30.
The present invention provides an apparatus for coupling a container of colorant to a feeder structure for a polymer processing machine. The coupling apparatus includes a tubular structure defining a passage through which the colorant can flow from the container to the feeder structure. An outlet portion of the tubular structure is configured to engage the feeder structure. An inlet portion of the tubular structure is configured to receive and support the container above the outlet portion.
In accordance with the invention, the coupling apparatus further includes a joint which supports the inlet portion of the tubular structure for movement relative to the outlet portion between an upright position and an overturned position when the outlet portion is engaged with the feeder structure. When the inlet portion is in its upright position, it is oriented to support the container in an overturned position from which the colorant can flow out of the container under the force of gravity. When the inlet portion is in its overturned position, it is oriented to receive the container in an upright position from which the colorant will not spill from the container.
In a preferred embodiment of the invention, the coupling apparatus includes a releaseable locking device which interacts with the joint to retain the inlet portion of the tubular structure releaseably in its upright position. The joint in the preferred embodiment is a hinge supporting the inlet portion of the tubular structure for movement relative to the outlet portion pivotally about a horizontal axis.
Further in accordance with the invention, the inlet portion of the tubular structure in the preferred embodiment is moveable relative to the output portion rotationally about a vertical axis when the inlet portion is in its upright position. This enables the container to swivel to a convenient position relative to the other parts of the colorant feeding system. A clamp retains the container releaseably in a selected position about the vertical axis by blocking such rotational movement of the inlet portion of the tubular structure.